Bond



Jan. 30, 1934.

BOND

Filed March 23, 1932 lllillllflllli llll INVENTOR- E. M. DEEMS 1,945,480

Patented Jan. 30, 1934 UNITED STATES PATENT OFFICE BOND Application March 23, 1932. Serial No. 600,595

Claims. (01. 173-280) This invention relates to conductors, more especially to conductors for connecting the adjacent ends of railway rails, particularly those for use in connection with railway track circuits.

5 It is well understood by those skilled in the railway signalling art, that a track circuit includes an insulated section of the trackway formed by placing insulating joints in each of the lines of rails, and by connecting a battery across the rails at one end, and a relay across the rails at the other end.

It is also well understood that the ordinary rail connecting or fish plates connecting the adjacent ends of the ordinary thirty-six foot sections arenot to be relied upon to furnish sufficient conductivity for the electrical energy which fiows in the rails from the battery at one end of the section to the relay at the other end thereof. This fact has necessitated a special bonding of each of the adjacent abutting rail ends within the section.

Great difficulties have been encountered in successfully bonding the adjacent abutting rail ends in track circuit sections because provision has to be made for many adverse conditions. A common method is to bond, from one rail web to the adjacent rail web, by means of one or a plurality of conductors of a length somewhat greater than the length of the fish plates. This meth- 0d of bonding exposes the bonding wires to mechanical injury, in that, they may become entangled with dragging parts from the rolling stock, or may actually get onto the top of the rail, and so be severed by the passage thereover of the wheels of rolling stock. In addition, they are very likely to be damaged by track men while working along the track, particularly when working in and about the rail joint, and more especially when tightening the bolts thereof, or replac- 49 ing the fish plates with new plates.

A very pronounced difficulty with the old type of bond is, that due to its length and in spite of its size as it may be commercially used, it does not ofier a conductivity as great as is desired.

The desired conductivity cannot be attained without enlarging the bond to a prohibitive extent.

Attempts have been made to increase the conductivity and decrease the mechanical disad- 50 vantages of bonds by applying a bond directly to the rail heads. Such a bond can be very short. as, compared with the previously described bond, therefore, for a given diameter has an increased conductivity in that it has less resistance. Such bonds have, in general, been applied to the head of the rail by electrical or flame welding.- Many competent engineers are adverse to applying any considerable degree of heat to the side of the ball of a rail, especially adjacent the end thereof, and this reluctance, considered by many to 0 be well founded, has militated against the use of such bonds.

A further difiiculty which has been met with in the type of bond applied directly to the rail heads is that it is particularly exposed to injury 68 by snow ploughs and ballast Spreaders. Both 01 these devices, and especially the ballast spreader, have parts which extend below the top surface of the head of the rail on the outside thereof. These parts, due to the swaying of the vehicle, 70 come in contact with the head of rail bonds and destroy them.

Attempts have been made to attach bonds to rail heads by drilling a cavity in the rail head and attaching the bond to a plug driven into the cavity. A difiiculty with this type of bond arises from the fact that it is necessary to drill a relatively deep hole in the head of the rail. This hole penetrated what might be called the active cross-sectional area of the head and to that ex tent weakened the rail head.

In my copending application Serial No. 538,943, filed May 21, 1931, I have illustrated, described, and claimed a type of bond for attachment to rail heads. This type of bond obviates many of the defects of the type of bond heretofore used and has many desirable virtues especially in that the cavity whichmust be formed in the head of the rail for the reception thereof is so shallow that it does not penetrate the active load sustaining cross-section of the rail. By reason of this fact incipient cracks which may develop in the rail head are not afiorded an easy opportunity to spread by reason of the cavity formed for the reception of the head of the rail bond, as that cavity does not closely approach the point of origin of the cracks.

I have discovered, in practice, that the type of. bond illustrated and described in my copending application, hereinbefore referred to, has a weakness in that it is subject to injury at the junction line of the surface in which the cavity is produced and the bond.

A principal object of this invention is to provide a bond of the type illustrated, described, and claimed in my copending application hereinbefore mentioned, of such construction that any tendency towards mutilation of the bond at the line of contact between the bond and the edge of the cavity in the rail head will be obviated.

Other objects and advantages will appear as the description of the particular physical embodiments selected to illustrate the inventiom progresses and the novel features will be particularly pointed out in the appended claims.

In describing the invention in detail and the particular physical embodiments selected to illustrate the invention, reference will be had to the accompanying drawing and the several views thereon, in which similar parts will be designated by similar characters throughout the several views, and in which:

Figure 1 is an elevational view of two abutting rail ends with a device of my invention in place thereon; Fig. 2 is a top plan view of the device as shown by Fig. 1, but with certain parts broken away and other parts in section to more clearly illustrate the construction; Fig. 3 is an enlarged fragmentary plan view of a portion of the device as shown in Fig. 2 illustrating the manner of fastening the bond in place; Fig. 4 is a view corresponding to Fig. 3, but showing the position of the parts in a completed bond; Fig. 5 is a view, corresponding to Fig. 3, but showing another modified form of a device of my invention.

Numerals 1 and 2 designate two adjacent rail ends. These rails are shown in elevation in Fig. 1 and in plan in Fig. 2. The webs are 3 and 4 and the heads, in the elevational view, extend between the lines 5 and 6. As shown in'Fig. 2', the fiange side of the rail is designated 7 and the outside edge is designated 8.

In order to electrically bond the rails 1 and 2 in accordance with my invention, I first form shallow cavities 9 and 10 in the head of the rail from the outside face thereof. These shallow cavities may be formed, and are preferably formed, by the use of an ordinary drill. These cavities are so shallow as to lie entirely without or substantially entirely without what might be called the active cross-section of the rail, that is, that portion of the cross-section of the rail least active in sustaining the stresses of a passing train. To this end applicant not only forms the cavities 9 and 10 very shallow, but also forms the cavities well down upon the side of the head of the rail, as most clearly shown by Fig. 1.

The conductor portion of the bond 11 is made of any suitable electrical conducting material, applicant prefers to make the bond of copper or partly of copper and partly of phosphor bronze as illustrated, described and claimed in my copending application Serial No. 596,939, filed March 5, 1932. Applicangalso prefers to form the conductor of laminae.

In order to attach the ends of the conductor 11 to the several rail heads, applicant employs a thimble, as 12 at each end of the conductor. This thimble 12 is formed substantially as an annulus with an end wall. The outside diameter of the thimble is such that it just snugly fits into the cavity 9 produced in the rail head. The

' end wall 13 of the thimble, as shown in Fig.

3, is slightly rounding as made in practice, that is, it is not made with a sharp conical point which will exactly fit into the end of the cavity in the rail'head.

The outer end of the thimble 12 is preferably bent=over, as at 14, to form a skirt. This skirt is slotted at 15 to receive the end of the conductor 11 so that the conductor may encircle the thimble 12 and be contained between the thimble 12 and the skirt 14. In order to make this junction both electrically and mechanically '16, best shown in its original form in Fig. 3.

that-no tendency to fracture the head 21 is prestrong it is welded or soldered in any of the well known and preferred ways.

In order to retain the thimble 12 within the cavity 9 of the rail 1, applicant employs a plug This plug, in the form shown, is circular in crosssection in a plane taken parallel to the conductor 11. It is, in the form shown in Fig. 3, slightly greater in diameter than its length from end to end measured along the axis of the thimble and for this reason I call it a disc. In the preferred form, as shown in Fig. 3, one end is a truncated cone and the other end a hemisphere.

Although applicant has illustrated his plug 16 in the most preferred form now known to him, nevertheless, it is to be understood that the plug 16 is in essence a disc and may well serve the purpose of applicant if made in a more simple and less complex form.

By reference to Fig. 3 it will be seen that the outside line 1'7 of greatest diameter of the plug 16 is inward of the line 8 of the face of the rail head, that is, it is inward of the line 18 of the junction of the edge of the cavity and the thimble. Careful study and experimentation with this type of bond has shown applicant that fracture or incipient fracture is likely to occur at the junction line 18. In order to avoidthis possible defect, applicant has devised the type of plug shown in the drawing which is characterized by the fact that the most outward line of greatest diameter is always inwards of the edge or line 18.

With the type of plug as shown by Fig. 3

firm connection between the rail and the thimble and the plug is secured by first inserting a suitable cylindrical tool as 19 within the thimble 12 and then forcing it with great pressure, as by striking with a hammer, against the plug 16. The result of this operation is to force the plug 16 and the thimble 12 into the form as shown by Fig. 4. When the parts are 'in the condition as shown in Fig. 4, the thimble 12 is forced tightly against the inside surface of the cavity 9, and the plug 16 is forced tightly'120 against the inside surface of the thimble 12 and against the surface of the end wall 13.

In forcing the plug 16 into the form as shown by Fig. 4 no pressure whatsoever has been brought upon the shell or thimble 12 along the line 18 so that there has been no tendency to fracture the thimble along this line. 7

In the form of bond shown by 5 the conductor 20 is secured in any appropriate manner to a solid head 21. This solid head has a cavity 22 therein of a depth-such that its end wall 23 is inward of the junctionline 24 between the plug and the face 8 of the rail. In firmly' attaching the plug lend 21 in the cavity of the rail, 9. tool is inserted within the cavity 22 abuttingthaend wall 23 thereof. When pressure is applied to such tool the bond is' thoroughly expanded within the cavity but no pressure comes upon the line of junction 24, so

. sented. The parts are made of such dimensions that when the portion 21 is fully expanded in the rail cavity, the conductor 20 is positioned slightly from the rail as at 25 so that it is not in danger of being broken off by pressure against the rail.

The hereinbefore described bond is very short and consequently has a relatively large electrical conductivity compared to its total weight. This 7 corrugated form, as shown by Fig. 1, provides for ample expansion and contraction due to changes.

of temperature or displacement of the rails. Its laminated structure provides extreme flexibility. The sleeve members 12 are readily attached to the conductor portion 11 and the sleeve portion 12 being preferably formed of a high conductivity metal such-as copper is readily welded or soldered to the conductor portion 11, and, due to the skirt portion 14, the laminae are firmly held together on the end mechanically thus neutralizing the forces tending to cause the laminae to spread. The contact between the outsideof the thimble and the inside surface of the cavity is intimate and of such a nature as to efl'ectually prevent the entrance of moisture. Excessive pressure is not needed upon the plug 16 to perform its proper functions of driving the thimble into intimate contact with the inner surface of the cavity, because the plug 18 is made preferably of fairly soft copper which not only is very malleable, but is a metal which will resist corrosion. so that ii the plug has been driven firmly into place, as shown by Fig. 4. corrosion will not take place between the plug and the sleeve so as to decrease the constant pressure exerted by the plug to keep the shell in electrical contact with the inside surface of the cavity in the rail.

Although I have particularly described particular physical embodiments of my invention and explained the construction, principle, and mode of operation thereof, nevertheless, I desire to have it understood that the form selected is mere- 1:! illustrative but does not exhaust the possible,

physical embodiments of the idea of means tin-'- derlying my invention.

What I claim as new and desire to secure by Letters Patent 0! the United States, 18:.

1. A rail bond comprising an electrical con-. ductor. a metallic thimble adapted to be partially inserted into a cavity in a rail. means electrically and mechanically connecting the thimble 2. m a rail bond, in combination: a metallic thimble having an end wall and adapted for insertion in a cavity in a rail; an electrical conductor attached to said thimble; and a metallic plug adapted to be inserted into said thimble; said 80 plug being formed of malleable metal and of such length that when in said sleeve abutting the end wall thereof and said sleeve. is positioned in the cavity abutting the end wall of the cavity all expansion laterally of the plug when pressed along lines parallel to the axis of the thimble will be exerted within that portion of the thimble that is entirely within the cavity; and means connecting said thimble electrically with a rail structure adjacent to the rail in which it is positioned.

8. The method of aflixing one end of a rail bond to a rail which consists in attaching an electrical conductor conductively to a contacting member bearing against the inside surfaces of a rail cavity and then expanding a body against those portions only of said member which are wholly within the rail cavity so as to hold the member tightly in contact with the said surfaces.

4. In a rail bond, in combination: a conduc- 13;) tor: hollow terminals, one at each end of the conductor; each of the terminals positioned partially within a cavity in a rail; discs, one for each terminal, each disc being of a diameter allowing I the disc to readily enter a hollow terminal and 135 each of said discs being readily flattened and thereby increased in diameter so as to retain the hollow terminals in the cavities in rails, and each of said discs being of a thickness such that upon being flattened and increased in diameter all of 110 the expanding disc will exert all of its pressure against that portion of the hollow terminals within the cavities,

5. The method of affixing one end of arail bond to a rail which consists in attaching an electrill: cal conductor conductively to a contacting member having a portion bearing against the inside surface of a rail cavity and then exerting pressure in such a manner that only that portion oi the contacting member within the cavity has 1 force exerted thereagainst whereby fracture of the contacting member along the line of juncture of the contacting body and the edge of the cavity is avoided. 1

- EDWARD M. 'DEEMS. 12: 

